U.S. patent application number 11/560754 was filed with the patent office on 2007-03-29 for integrated infusion and aspiration system and method.
Invention is credited to T. Wade Fallin, E. Marlowe Goble, Mark E. Howard, Jeffrey T. Mason.
Application Number | 20070073268 11/560754 |
Document ID | / |
Family ID | 31495252 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070073268 |
Kind Code |
A1 |
Goble; E. Marlowe ; et
al. |
March 29, 2007 |
Integrated Infusion and Aspiration System and Method
Abstract
An integrated infusion and aspiration system includes of a flow
control system and a catheter assembly. The catheter assembly
includes an infusion catheter and an aspiration catheter, each
having ports located at the distal end of thereof. The distal ends
of the catheters are separated so that the aspiration catheter
ports can be positioned on an opposing side of a surgical wound
site from the infusion catheter ports. Methods of operation of the
integrated infusion and aspiration system provides for
uninterrupted aspiration with concurrent controlled delivery of an
infusion solution such that the infusion solution is substantially
evenly dispersed of over the wound site.
Inventors: |
Goble; E. Marlowe; (Logan,
UT) ; Howard; Mark E.; (San Diego, CA) ;
Mason; Jeffrey T.; (Escondido, CA) ; Fallin; T.
Wade; (Hyde Park, UT) |
Correspondence
Address: |
DAVID W. MEIBOS;MEDICINELODGE, INC.
180 South
600 West
Logan
UT
84321
US
|
Family ID: |
31495252 |
Appl. No.: |
11/560754 |
Filed: |
November 16, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10896515 |
Jul 22, 2004 |
7163521 |
|
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11560754 |
Nov 16, 2006 |
|
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|
10218106 |
Aug 12, 2002 |
6893414 |
|
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10896515 |
Jul 22, 2004 |
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Current U.S.
Class: |
604/508 ;
128/898 |
Current CPC
Class: |
A61M 1/0058 20130101;
A61M 27/00 20130101; A61M 25/007 20130101; A61P 23/00 20180101;
A61M 2025/018 20130101; A61M 1/0023 20130101; A61M 2025/0004
20130101; A61M 2025/0039 20130101; A61M 1/75 20210501; A61M
2025/0037 20130101; A61M 25/0021 20130101 |
Class at
Publication: |
604/508 ;
128/898 |
International
Class: |
A61M 31/00 20060101
A61M031/00 |
Claims
1. A method for percutaneous infusion and aspiration of an internal
wound site, the method comprising: infusing a wound site with a
dose of a solution at a periodic interval; aspirating the wound
site at a first flow rate during the infusion of the solution and
for a first time period thereafter; and aspirating the wound site
at a second flow rate after expiration of the first time period but
prior to the next infusing of the solution, the second flow rate
being greater than the first flow rate.
2. The method of claim 1, wherein the periodic interval between
infusions is greater than the sum total of the duration of the
infusion and the predetermined time period.
3. The method of claim 1, wherein the aspirating is continuous.
4. The method of claim 1, wherein the solution comprises an
analgesic, anesthetic, antibiotic, antiseptic, anticoagulant,
anti-inflammatory, or combinations thereof.
5. A method for percutaneous infusion and aspiration of an internal
wound site, the method comprising: infusing the wound site with a
dose of a solution; aspirating the wound site at a first flow rate
during the infusion of the solution; and aspirating the wound site
at a second flow rate either immediately upon completion of
infusing the solution or at a time period after completion of
infusing the solution.
6. The method of claim 5, further comprising repeating at periodic
intervals the act of infusing the wound site with a dose of a
solution.
7. The method of claim 6, wherein the aspirating is continuous.
8. The method of claim 5, wherein the solution comprises an
analgesic, anesthetic, antibiotic, antiseptic, anticoagulant,
anti-inflammatory, or combinations thereof.
9. A method for percutaneous infusion and aspiration of an internal
wound site, the method comprising: infusing the wound site with the
solution at a substantially constant rate; and aspiration the wound
site at alternating flow rates.
10. A method of claim 9, wherein the aspiration is continuous.
11. The method of claim 9, wherein the solution comprises an
analgesic, anesthetic, antibiotic, antiseptic, anticoagulant,
anti-inflammatory, or combinations thereof.
12. A method for percutaneous infusion and aspiration of an
internal wound site, the method comprising: passing a catheter
assembly through a single incision, the catheter assembly
comprising: an aspiration catheter having at least one port formed
thereon; and an infusion catheter having at least one port formed
thereon; positioning the at least one port of the aspiration
catheter on one side of the internal wound site and the at least
one port of the infusion catheter on a substantially opposing side
of the internal wound site; periodically infusing the wound site
with a dose of a solution through the infusion catheter; and
aspirating the wound site through the aspiration catheter at
alternating flow rates.
13. The method as recited in claim 12, wherein the act of passing
the catheter comprises at least a portion of the aspiration
catheter or infusion catheter being disposed within a lumen of the
other of the aspiration catheter or infusion catheter.
14. The method of claim 12, wherein the aspirating is
continuous.
15. The method as claim 12, wherein the at least one port of the
aspiration catheter and the at least one port of the infusion
catheter are each disposed outside of a blood vessel.
Description
CROSS-REFERENCE TO RELATED DOCUMENTS
[0001] This application is a continuation of:
[0002] U.S. patent application Ser. No. 10/896,515, filed Jul. 22,
2004, which carries Applicants' Docket No. 13447.26.1 and is
entitled INTEGRATED INFUSION AND ASPIRATION SYSTEM AND METHOD,
which is a divisional of:
[0003] U.S. patent application Ser. No. 10/218,106, filed Aug. 12,
2002, now U.S. Pat. No. 6,893,414, which carries Applicants' Docket
No. 13447.26 and is entitled INTEGRATED INFUSION AND ASPIRATION
SYSTEM AND METHOD.
[0004] All of the above are incorporated herein by reference.
FIELD OF THE INVENTION
[0005] The present invention relates generally to the post-surgical
treatment of closed wounds and specifically to methods and systems
for concurrent aspiration and infusion of a wound site to manage
pain, swelling, bleeding and infection.
BACKGROUND OF THE INVENTION
[0006] One of the most difficult aspects of enduring a major
surgical procedure is coping with the post-operative pain and
swelling. Commonly, opioid analgesics, sometimes referred to as
narcotics, are administered post-operatively to counter the pain
associated with wound healing and recovery. However, the use of
systemic opioid analgesics, whether administered by oral,
intramuscular, or intravenous methods, includes a host of possible
undesirable side effects, including: respiratory depression, renal
function depression, nausea, constipation, ataxia, confusion,
sweating, and itching. The length of hospital stay for patients
undergoing a major surgical procedure is, in part, determined by
the need to monitor and control the side effects of systemically
administered opioid analgesics.
[0007] More recently, infusion pumps have been used to
percutaneously deliver local anesthetics directly to the surgical
wound. Thus, many of the undesirable side effects of systemic
opioid analgesics are avoided. Furthermore, medication dosage is
considerably less than systemic delivery since the medication is
delivered directly to the affected site. However, contemporary
percutaneous pain medication infusion pumps do not provide
consistent relief of pain.
[0008] Another challenge associated with percutaneous pain
medication infusion pumps is the need to concurrently address
edema, or fluid build-up and swelling, at the wound site.
Aspiration of excess fluid has been attempted by the use of a
separate and discrete percutaneous catheter connected to a vacuum
source. However, concurrent use of a pain medication infusion pump
and an aspiration catheter creates two significant compromises to
the patient. First, two percutaneous catheters, one for the
aspiration catheter and one for the infusion pump, potentially
doubles the risk of infection since two percutaneous tracts are
maintained. Second, an aspiration catheter coupled with an active
vacuum source that is designed for the removal of fluid build-up
tends to remove the infused pain medication before it has
effectively produced the desired local anesthetic effect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various embodiments of the present invention will now be
discussed with reference to the appended drawings. It is
appreciated that these drawings depict only typical embodiments of
the invention and are therefore not to be considered limiting of
its scope.
[0010] FIG. 1 is a schematic view of an integrated infusion and
aspiration system applied to the knee of a patient.
[0011] FIG. 2 is a cross sectional side view of the catheter
assembly shown in FIG. 1 taken along sections lines 2-2.
[0012] FIG. 3 is a cross section side view of an alternative
embodiment of the catheter assembly shown in FIG. 2.
[0013] FIG. 4 is a schematic view of an alternative embodiment of
the catheter assembly of the integrated infusion and aspiration
system shown in FIG. 1.
[0014] FIG. 5 is a schematic view of another alternative embodiment
of the catheter assembly of the integrated infusion and aspiration
system shown in FIG. 1.
[0015] FIG. 6 is a schematic view of still another alternative
embodiment of the catheter assembly of the integrated infusion and
aspiration system shown in FIG. 1.
[0016] FIG. 7 is a schematic view of yet another alternative
embodiment of the catheter assembly of the integrated infusion and
aspiration system shown in FIG. 1.
[0017] FIG. 8 is a cross sectional side view of the catheter
assembly shown in FIG. 6 taken along section lines 8-8.
[0018] FIG. 9 is a cross sectional side view of an alternative
embodiment of the catheter assembly shown in FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Shown in FIG. 1 is one embodiment of an integrated infusion
and aspiration system 35 incorporating features of the present
invention. System 35 is applied to a knee 25 of a patient to treat
a surgical wound that would result from, for example, a total knee
arthroplasty surgery. While FIG. 1 demonstrates use of one
embodiment of integrated infusion and aspiration system 35 for a
knee, it is understood that the present invention can be used for
any internal body wound created by surgery, trauma, or disease.
[0020] In general, integrated infusion and aspiration system 35
comprises a catheter assembly 20 coupled with a flow control system
19. Viewed as a whole, catheter assembly 20 has a proximal section
21, an opposing distal section 22, and a middle section 23
extending therebetween. More specifically, catheter assembly 20
comprises an infusion catheter 10 and an aspiration catheter 15.
Infusion catheter 10 comprises a proximal section 40, an opposing
distal section 42, and a middle section 44 (see FIG. 2) extending
therebetween. Distal section 42 terminates at a distal end tip 17.
Infusion catheter 10 bounds a first lumen 46 (FIG. 2) that extends
along the length thereof and exits through an end port 26 at distal
end tip 17. A plurality of longitudinally spaced apart side ports
16 extend through infusion catheter 10 at distal section 42 so as
to communicate with first lumen 46. In alternative embodiments, the
plurality of side ports 16 can be eliminated or replaced with one
or more side ports. Furthermore, side ports 16 can be spaced
laterally and/or radially.
[0021] Aspiration catheter 15 comprises a proximal section 50, an
opposing distal section 52, and a middle section 54 extending
therebetween. Distal section 52 terminates at a distal end tip 12.
Aspiration catheter 15 bounds a second lumen 56 (FIG. 2) that
extends along the length thereof and exits through an end port 27
at distal end tip 12. A plurality of spaced apart side ports 11
extend through aspiration catheter 15 at distal section 52 so as to
communicate with second lumen 56. As with infusion catheter 10, the
plurality of side ports 11 can be eliminated or replaced with one
or more side ports 11. Furthermore, side ports 11 can be spaced
laterally and/or radially.
[0022] In one embodiment, the plurality of ports of infusion
catheter 10 and aspiration catheter 15 each have a predetermined
number and a predetermined spacing, the number and spacing of the
plurality of ports on infusion catheter 10 being substantially the
same as the number and spacing of the plurality of ports on
aspiration catheter 15. In other embodiments, the number and/or
spacing of the ports on the infusion catheter 10 and aspiration
catheter 15 can be different.
[0023] In the embodiment of catheter assembly 20 shown in FIG. 1,
infusion catheter 10 passes through a sidewall of aspiration
catheter 15 and into second lumen 56 at a proximal junction 60.
This is typically accomplished by forming a hole in the sidewall of
aspiration catheter 15 and then passing infusion catheter 10
therethrough. Once infusion catheter 10 is positioned, infusion
catheter 10 and aspiration catheter 15 are sealed together at the
hole such as by welding, adhesive, or other conventional forms.
[0024] Infusion catheter 10 travels distally within second lumen 56
and exits aspiration catheter 15 through end port 27 at distal end
tip 12. Thus, as shown in FIG. 2, infusion catheter 10 occupies an
internal, coaxial position with respect to aspiration catheter 15
between proximal junction 60 and distal end tip 12 of aspiration
catheter 15.
[0025] It is noted that the outer diameter of infusion catheter 10
is smaller than the inner diameter of aspiration catheter 15 so
that fluid is free to flow within second lumen 56 of aspiration
catheter 15. Furthermore, this arrangement provides the advantage
of protecting infusion catheter 10 from possible kinking or
pinching when is it positioned internal to the more substantially
larger sized aspiration catheter 15. Another advantage of this
arrangement is that by positioning infusion catheter 10 within
aspiration catheter 15, only a single tract through the skin is
required to pass both catheters 10 and 15 from an extracorporeal
site to the internal wound site.
[0026] Continuing with the embodiment of catheter assembly 20 shown
in FIG. 1, infusion catheter 10 extends distally from the distal
end tip 12 of aspiration catheter 15 a predetermined distance so
that distal end tips 12 and 17 are spaced apart. The spaced
distance is sufficient so that ports 16 and 26 of infusion catheter
10 and ports 11 and 27 of aspiration catheter 15 can be positioned
on opposing sides of a wound. The spacing between ports 11, 27 and
16, 26 is dependent upon wound size, but in one embodiment is more
than ten times the largest external transverse dimension of
aspiration catheter 15.
[0027] As shown in FIG. 1, flow control system 19 comprises a flow
control 5, a pump 2, and medication reservoir 1 each operably
coupled with proximal section 40 of infusion catheter 10.
Similarly, a flow control 6, pump 4, and aspiration reservoir 3 are
operably coupled with proximal section 50 of aspiration catheter
15. Reservoirs 1 and 3 can comprise a flexible bag, such as an IV
bag, a syringe barrel, or any other conventional hard of soft sided
container adapted to hold a fluid.
[0028] The infusion solution used by the present invention can
contain a number of different medications to best address the post
surgical concerns of the wound. For example, the infusion solution
can contain, separately or in combination, an analgesic agent, an
anesthetic agent, an antibiotic, an antiseptic, an anticoagulant,
or an anti-inflammatory. Thus, in addition to pain relief provided
by analgesic and anesthetic agents, concurrent prophylactic
treatment for infection and treatment to reduce swelling can be
achieved by including an antibiotic and anti-inflammatory in the
infusion solution.
[0029] Pumps 2 and 4 can be any standard pump known by those
skilled in the art, such as a squeeze bulb, syringe, syringe pump,
syringe plunger, centrifugal pump, persistaltic pump, diaphragm
pump, screw pump, IV pump, or the like. The flow controls 5 and 6
can be any standard flow control device known to those skilled in
the art, such as an orifice, capillary tube, or valve. Valves
include solenoid valves, servo valves, and flow restricting valves,
such as a needle valve, gate valve, pinch valve, and the like.
Connected to pump 2 is a power source 7, and connected to pump 4 is
a power source 8. Power sources 7 and 8 can be selected from a
number of power sources known by those skilled in the art,
including manual actuation, spring, dc motor, ac motor, and the
like.
[0030] When the power sources 7 and 8 and flow controls 5 and 6 are
passive devices, such as a spring or orifice, a separate controller
is not required. However, when the power sources 7 and 8 and/or
flow controls 5 and 6 are not passive, a controller 9 is connected
thereto. Controller 9 is generally electronic, and preferably
controller 9 is a microprocessor based control device.
[0031] In one embodiment, reservoirs 1 and 3, pumps 2 and 4, flow
controls 5 and 6, powers sources 7 and 8 and controller 9
collectively comprise flow control system 19. Although FIG. 1 shows
the various elements of flow control system 19 in a defined order,
it is appreciated that the various elements can be reorganized in a
variety of different orientations using different combination of
parts. For example, one configuration for flow control system 19
comprises the following selections: flow control 5 is a solenoid
valve, medication reservoir 1 is a syringe barrel, pump 2 is a
syringe plunger, and power source 7 is a spring which is disposed
between the syringe plunger and the syringe barrel.
[0032] In this configuration, the syringe plunger is initially
drawn back relative to the syringe barrel so as to fill the syringe
barrel with a desired solution. In so doing, the resilient spring
is stretched so that there is a constant force attempting to drive
the syringe plunger back into the syringe barrel and, in turn,
discharge the solution therefrom. The syringe barrel is connected
in fluid communication with the proximal section of infusion
catheter 10. Accordingly, the solution is passed from the syringe
barrel, through infusion catheter 10, and out through ports 16, 26.
The solenoid valve is disposed so as to selectively control the
flow of solution from the syringe barrel into the infusion
catheter.
[0033] Continuing with the example, flow control 6 is an adjustable
flow restricting valve, such as a pinch valve, aspiration reservoir
3 is a syringe barrel, pump 4 is a syringe plunger, and power
source 8 is a spring positioned between the syringe barrel and the
syringe plunger. In this embodiment, the spring is compressed as
the syringe plunger is pressed into the syringe barrel. The syringe
barrel is in fluid communication with the proximal section of
aspiration catheter 15. In this configuration, the spring produces
a constant force seeking to push the syringe plunger out of the
syringe barrel. As the syringe plunger is pushed out of the syringe
barrel by the spring, a relative vacuum is produced which causes
fluid to be sucked into aspiration catheter 15 through ports 11, 27
and into the syringe barrel.
[0034] Controller 9 is connected to the flow control 5 and the flow
control 6, but not to power sources 7 and 8 since they are passive
devices. Controller 9 is a microprocessor with embedded firmware
that selectively opens and closes the flow control 5, the solenoid
valve, and also increases or decreases the flow rate through
partial actuation of flow control 6, the pinch valve.
[0035] An alternative configuration for flow control system 19 is
comprised of the same selections as above, except that flow control
5 is an orifice that creates a flow rate proportional to the fluid
pressure. Furthermore, the controller 9 is only connected to flow
control 6, since flow control 5 is, in this instance, a passive
device. With this configuration, a relatively constant flow rate of
the infusion solution is achieved while the aspiration flow rate
can be increased or decreased based the amount and time of
accumulation of the infusion solution at the wound site.
[0036] As discussed above, during operation catheter assembly 20 is
inserted through a single incisions 62 in the skin so that at least
a portion of ports 11, 27 and 16, 26 are positioned on opposing
sides of an internal wound site. In one embodiment, the ports 11,
27 and 16, 26 and corresponding catheters are disposed outside of a
blood vessel. Catheter assembly 20 is coupled with flow control
system 19. In one method of operation, fluid control system 19
administers at set periodic intervals a dose of infusion solution
to infusion catheter 10. The dose of infusion solution passes
through infusion catheter 10 and out through ports 16, 26 to one
side of the wound site.
[0037] Simultaneously with the infusion of the dose, and for a
predetermined time period thereafter, flow control system 19 draws
fluid on the opposite side of the wound site into aspiration
catheter 15 by way of ports 11, 27 at a first flow rate. Ports 16,
26 and ports 11, 27 are positioned so that aspiration of fluid by
aspiration catheter 15 causes the infused dose to uniformly travel
over the wound site. At the conclusion of the predetermined time
period following the infusion, fluid is drawn into aspiration
catheter 15 at a second flow rate, the second flow rate being
faster than the first flow rate. When the next dose of infusion
solution is administered, the flow rate in aspiration catheter 15
is again lowered to the first flow rate and the process is
repeated.
[0038] Although not required, in one method of operation the flow
in aspiration catheter 15 is never interrupted, i.e., is
continuous, throughout the repeated periodic infusion of the
infusion solution. This is because a standing fluid column of blood
and other body fluids is likely to coagulate, thereby clogging the
aspiration catheter 15.
[0039] By way of example of the operation process, in the case of
the administration of a local anesthetic, such as lidocaine,
bupivacaine, or ropivicaine, the dose is between about 0.5 cc and
about 4 cc. The set periodic interval between administration of the
doses is approximately one hour. The first flow rate at which fluid
is drawn into aspiration catheter 15 during administration of the
dose and the predetermined time period thereafter is between about
10% to about 30% of the dose per hour. The predetermined time
period at which the aspiration catheter 15 operates at the first
flow rate following infusion is equal to or longer than the time
required for the medications in the infusion solution to
effectively treat the wound. As such, the length of the
predetermined time period is typically between about 5 minutes to
about 15 minutes. Following the predetermined time period but prior
to administration of the next dose, the flow rate in the aspiration
catheter is controlled at a rate generally between about 4 cc/hr
and about 50 cc/hr, and preferably between about 10 cc/hr and about
30 cc/hr.
[0040] The above method of operation provides a resident time for
the infusion solution that allows the infusion solution to
effectively treat the wound, and thereafter the infusion solution
along with other accumulated body fluids are rapidly evacuated from
the wound site to reduce swelling and to ameliorate associated
pain.
[0041] In an alternative method of operation, each dose is
delivered over an extended period of time such that aspiration
catheter 10 aspirates at the first flow rate during infusion of a
discrete dose and then immediately aspirates at the second flow
rate upon completion of infusing that dose. As such, there is no
delay, i.e., "predetermined time period," between completion of the
infusion and changing the aspiration to the second flow rate. This
alternative method of operation is an advantage where low pressure
injections are necessary to prevent disruption of delicate internal
structures that are starting to heal. Although less efficient in
some situations, it is also appreciated that aspiration can be
changed to the increased second flow rate prior to completion of
infusion of a discrete dose.
[0042] In yet another alternate method of operation, the infusion
solution is delivered at a relatively constant flow rate. In the
case of the administration of a local anesthetic, such as
lidocaine, bupivacaine, or ropivicaine, the flow rate of the
infusion solution is preferably between about 0.5 cc/hr and about
4.0 cc/hr. The flow rate within aspiration catheter 15 is cycled
between a low flow rate, generally at a rate between 10% and 30% of
the infusion solution flow rate, and a high flow rate, generally
between 4 cc/hr and 50 cc/hr, and preferably between 10 cc/hr and
30 cc/hr. The cycle for the low flow rate generally endures for 15
to 30 minutes, and the low flow rate cycle generally repeats
approximately every 60 minutes. Thus, this alternate method of
operation provides for a period time when the flow rate within
infusion catheter 10 is higher than the flow rate within aspiration
catheter 15, thus creating an accumulation of the infusion solution
so that it may effectively treat the wound.
[0043] As previously, mentioned, contemporary percutaneous pain
medication infusion pumps do not provide consistent relief of pain.
It is theorized that this is because the medication that egresses
from the percutaneous catheter is not fully bathing the entire
volume of the wound site. Many of these infusion devices rely on
very low flow rates of 0.5 cc to 4.0 cc per hour, and localized
pooling of the medication can occur, leaving other portions of the
wound untouched by the pain medication.
[0044] Based on the foregoing, integrated percutaneous infusion and
aspiration system 35 takes advantage of the presence of a relative
negative pressure source, or vacuum, provided within aspiration
catheter 15. The negative pressure created by aspiration catheter
is used in the present invention to control the flow of the
infusion solution as it egresses from infusion catheter 10 so as to
cause the infusion solution to perfuse the entire wound site as it
travels toward aspiration catheter 15. The multitude of ports on
both infusion catheter 10 and aspiration catheter 15 provide an
array of opposing egress and ingress sites such that cross flow can
be created between the two catheters to fully bathe the wound site
with the infusion solution.
[0045] Furthermore, although not required, by integrating infusion
catheter 10 with aspiration catheter 15, catheter assembly 20 can
be efficiently and cleanly inserted into a single percutaneous
tract to the wound. As a result, further incisions are not required
and the potential for infection is minimized.
[0046] Furthermore, as discussed above, to achieve the desired flow
of the infusion solution across the wound and the desired residency
time of the infusion solution, a coordinated operation of the
infusion and aspiration catheters has been developed. The flow rate
within the aspiration and infusion catheters are controlled and
synchronized to ensure that the infusion solution is not evacuated
too quickly and to further ensure that the flow in the aspiration
catheter is uninterrupted in order to minimize the potential for
clot formations within the aspiration catheter that might otherwise
clog the aspiration catheter.
[0047] Flow control system 19 can be connected to a number of
different embodiments of catheter assembly 20. Alternate
embodiments of catheter assembly 20 are shown in FIGS. 3-9 with
like elements being identified by like reference characters. For
example, depicted in FIG. 3 is a transverse cross sectional view of
a catheter assembly 38. As discussed above with regard to FIG. 2,
in catheter assembly 20 infusion catheter 10 and aspiration
catheter 15 are discrete catheters where, for a portion of the
length, infusion catheter 10 resides within aspiration catheter 15.
In contrast, although at least a portion of infusion catheter 10
resides within aspiration catheter 15 in catheter assembly 38,
infusion catheter 10 and aspiration catheter 15 are integrally
formed as a single unit, i.e., they share a common sidewall. In
this embodiment, either a separate catheter or a separate portion
of catheters 10 and 15 is used to connect one and/or both of the
integrally formed catheters to flow control system 19.
[0048] Depicted in FIG. 4 is an alternative catheter assembly 64
where aspiration catheter 15 has an outside diameter smaller than
the outside diameter of infusion catheter 10. In this embodiment,
aspiration catheter 15 passes through the sidewall of infusion
catheter 10 at proximal junction 60 so as to be disposed within
first lumen 46 of infusion catheter 10. Aspiration catheter 15
extends distally within infusion catheter 10 and exits through end
port 27 at distal end tip 17. Aspiration catheter 15 then continues
to project beyond distal end tip 17 of infusion catheter 10. As
with FIGS. 2 and 3, the coaxial portion of catheter assembly 64 can
either comprise two discrete catheters or a single integrally
formed catheter.
[0049] FIG. 5 shows a catheter assembly 66 similar to catheter
assembly 20 shown in FIG. 1. In contrast to infusion catheter 10
exiting aspiration catheter 15 at distal end tip 12, however,
infusion catheter 10 exits aspiration catheter 15 by passing
through the sidewall thereof proximal of distal end tip 12. As a
result catheter assembly 66 is bifurcated at both opposing ends.
Although the bifurcated distal end of infusion catheter 10 is shown
as being longer than the free distal end of aspiration catheter 15,
in alternative embodiments the bifurcated distal ends can be the
same length or the distal end of aspiration catheter 15 can be
longer.
[0050] FIG. 6 shows a catheter assembly 68 similar to catheter
assembly 64 shown in FIG. 4. Like catheter assembly 66 shown in
FIG. 5, however, aspiration catheter 15 exits infusion catheter 10
by passing through the sidewall thereof proximal of distal end tip
12. Accordingly, catheter assembly 68 is also bifurcated at both
opposing ends.
[0051] FIG. 7 shows a catheter assembly 70 wherein a least a
portion of middle sections 42 and 52 of infusion catheter 10 and
aspiration catheter 15, respectively, are integrally joined in a
side-by-side arrangement. The opposing ends of catheter assembly 70
have been bifurcated. Depicted in FIG. 8 is a transverse cross
sectional side view of one embodiment of the side-by-side
arrangement. This integral connection between catheters 10 and 15
enables catheter assembly 70 to be inserted through a single
incision in the skin.
[0052] Finally, depicted in FIG. 9 is a catheter assembly 72 which
comprises two discrete catheters 10 and 15. At least a portion of
the middle sections 42 and 52 of catheters 10 and 15, respectively,
are held together by an encircling outer tube 74. Outer tube 74 can
be replaced by a wrap or a variety of other forms of
connectors.
[0053] The present invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. Thus the described embodiments are to be
considered in all respects only as illustrative and not
restrictive. The scope of the invention is, therefore, indicated by
the appended claims rather than by the foregoing description. All
changes which come within the meaning and range of equivalency of
the claims are to be embraced within their scope.
* * * * *